On June 9, 2008, at least 60 dolphins stranded along the coast of
Cornwall, England, in what was by far the largest common dolphin
mortality ever seen in British waters. For hours, rescuers tried
to lead them back to sea — often unsuccessfully, as some of the
animals were panicked and others just milled about in tight
circles, resistant to saving. The forensic investigation that
followed involved 24 experts from five countries and multiple
government agencies.

For several days before the strandings, the British Royal Navy
ran a large, multinational event (which included the U.S. Navy
and involved active sonar and other disruptive activities) off
the Cornish coast. That event, the investigators concluded, was
closely correlated in space and time with the dolphins entering
Falmouth Bay and eventually coming ashore. All other possible
causes — disease, algal blooms, malnourishment — were eliminated.
[ Worst-Ever
Right Whale Die-Off Continues to Puzzle ]

The implication of naval exercises in a mass stranding will come
as no surprise to those who have followed this issue in the
United States. Nor will the Royal Navy's perfunctory denials in
media accounts, which seem awfully similar to what we have heard
over the years from the U.S. Navy.

In the case of mass strandings, what Navy officials always seem
to demand after the fact is some definitive, minute-by-minute
record of the victims' movements before beaching, as though it
were possible to
stick a tag on every whale and dolphin in the sea. Until
biologists can provide that infeasible level of proof, the U.S.
Navy refuses responsibility. But really, the Cornwall case is
simple: a gun was fired, there were bodies, and no one else was
in the room.

It's long past time for navies on both sides of the Atlantic to
stop denying the obvious and do something meaningful to reduce
harm, like putting especially vulnerable habitat off-limits to
dangerous training. Unfortunately, in the United States, that may
be something we have to fight for.

The reason is that
proposed federal regulations would permit the U.S. Navy to
harm marine mammals more than 30 million times over the next five
years. This gargantuan number encompasses more than 5 million
instances of temporary hearing loss — a significant impact for
species like whales and dolphins that depend on hearing for their
survival. And, it includes more than 10,000 cases of permanent
injury and nearly 350 deaths from underwater explosions, vessel
collisions and sonar exercises. Of course these are the U.S.
Navy's estimates; the reality could be even worse.

In Southern California, which sees the lion's share of U.S. Navy
training on the West Coast, biologists are concerned that the
U.S. Navy's range has become
a population sink for deep-diving beaked whales, a family of
marine mammal species that is acutely vulnerable to high-powered
naval sonar. And, new research on the same range shows that U.S.
Navy sonar
silences the foraging calls of blue whales over vast
distances. That's a big problem since Southern California
represents a globally important foraging area for that endangered
species.

The U.S. Navy, still in denial mode, likes to claim that it has
safely operated off California and other places for decades, but
just like in Cornwall, that argument is wearing very thin.

Denial has its consequences, however. Neither the latest science
nor its own dramatic estimates of harm has moved the U.S. Navy to
identify better means of protecting whales and other marine life.
Instead, it is proposing the same meager protective measures —
visually monitoring a narrow strip around its vessels — that the
scientific community and the courts have repeatedly found
inadequate. By contrast, avoiding important habitat is
universally acknowledged to be the most effective available
measure.

More than 550,000 people have signed a petition at
Signon.org calling for an end to the killing and harassment
of marine mammals by U.S. Navy sonar. With the new investigative
findings in Britain adding to the pile of evidence of harm,
perhaps now the U.S. authorities will do the right thing. Denial
is no longer an option.

The views expressed are those of the author and do not
necessarily reflect the views of the publisher.This
article was originally published on LiveScience.com.